(1) Field of the Invention
An electrical component lead wire cutting and clinching mechanism.
(2) Summary of the Prior Art
In assembling axial lead components to printed circuit boards, the component lead wires are inserted down through predetermined openings in the board. Thereafter, a cut-clinch mechanism, located beneath the board, cuts off the excess lead wire and bends over or clinches the lead wire to the underside of the board to securely attach the component to the board. This permits the board to be handled during the remaining assembly operations prior to permanently attaching the components to the board as by wave soldering, for example.
In this lead wire cutting and clinching operation, a pair of opposed cut-clinch head assemblies are positioned so that the lead wires can be received between a pair of knives on each head assembly that cut and clinch the lead wire. In this operation, the head assembly is mounted on a mechanism for moving the head assembly toward and away from the board. This permits the cut-clinch operation to be performed with the head assembly in a raised position and in the lowered position, adequate clearance is provided for shifting movement of the board between successive operations.
In addition, it is desirable to have the opposed head assemblies mounted for movement toward and away from one another so that variable spaced leads of different lengths of components can be cut and clinched.
U.S. Pat. Nos. 3,429,170, 3,986,533, 4,153,082 and 4,288,914 illustrate various types of cut-clinch mechanisms that are adapted to cut off the component lead wire beneath the board and bend the lead wire to secure the component to the board. All of these prior art devices, however, have the head assemblies mounted on a common drive mechanism for vertical movement which maximizes the mass that must be moved vertically during the various sequential operations of the cut-clinch mechanism.
None of the prior art discloses using a common drive for varying the spacing between the opposed cut-clinch head assemblies and using separate drives for raising and lowering the head assemblies during the successive operations of the component insertion operation.